Ence white and samuel s



-3. T. STARR DENTAL ENGINE HAND PIECE.

,870. Patented July Z9, 1884.

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ELI T. STARR, OF PHILADELPHIA, PENNSYLVAIA, ASSIGNOR TO J. CLAR- ENCE WHITE AND SAMUEL S. WHITE, JR., EXECUTORS OF SAMUEL S.

WHITE, DECEASED.

DENTAL-ENGINE HANDHPECE.

SPECIFICATION forming part of Letters Patent No. 302,870, dated July 29, 1834.

Application led May G, 1878.

T @ZZ whom it 'may cm1/cern:

Beit known that I, ELI T. STARR, of the city and county of Philadelphia, and State of Pennsylvania, have invented certain new and useful Improvements in Dental-Engine Hand- Pieces, of which the following is a specification.

My invention relates, more particularly, to a hand-piece of the class in which the operaio tor may simultaneously and by a single movement stop the rotation of the tool-holder without interfering with the driving-power, and unlock or disengage the fastenings which secure the operating-tool inside the holder; and

I 5 it constitutes an improvement upon the handpiece shown in Letters Patent of the United States granted to John WV. Gilbert, January 22, 187s, as No. 199,431, which is the only i11- stance prior to my invention, so far as I am 2o aware, in which this simultaneous-movement principle has been embodied. There is also a class of hand-pieces in which the nnclutching of the tool-holder from the drivingpower to place the instrument completely under the control ofthe operator is effected independently of the disengagement of the tool- ]ocking devices, which latter devices require a different movement from that which stops the rotation of the holder to release them from 3o engagement with the operating-tool, as shown in Letters Patent granted, respectively, to the said Gilbert, January 5, 1875, and to myself, December 5, 1876 and I contemplate the em ployment of some of the improvements hereinafter specied in hand-pieces of this latter class, as well as in other styles of hand-pieces not here :necessary to mention. y

The objects of the first part of my present invention are to improve the construction of 4o a hand-piece embodying'the principle of simultaneous disconnection of the chuck and disengagement of the tool-lock; to render such a hand-piecemore efficient, perfect in its operation, and convenient in use; and, also, to i5 adapt it to the well-known S."S. White Dental Engine, although I am aware that the said Gilbert has suggested that hisinvention might be so applied. y

To these ends the first part of my invention consists in combining a hand-piece cas- 5o ing, a sectional socketed spindle or chuck having bearings in said casing, a clutch between the chuck-sections, arocking or laterally-moving tool-locking latch or device carried by said chuck, and a controlling-sleeve acting both upon said clutch and said rocking-latch to simultaneously disengage the chuck-sections and rock the latch, to enable an operating-tool to be inserted in or withdrawn from the chucksocket.

The object of the next part of my invention is to provide a positively-operated pivoted latch-tool lock more especially adapted for a simultaneous-movement7 hand-piece; to which end my improvement consists in a pivoted catchv or latch provided in front of its pivot with a downwardly-projecting or hooked end and an inclined or flattened surface, for

engagement, respectively, with the grooved shank and inclined or flattened driving end of an operating-tool, and in rear of said pivot with an upwardly-projecting or gooseneck end, by which the latch is rocked upon its pivot to engage its front end with ordisengage it from the tool-shank.

This part of my invention further consists in the combination, in a dental-engine handpiece, of a rotary chuck or mandrel, a pivoted latch carried thereby, having a goose-neck end or inclined surface upon both its upper and lower edge, and an endWise-moving springsleeve revolving with the chuck, enveloping and controlling the pivoted latch.

This part of' my invention further consists in a pivoted tool-locking latch having a projecting or goose-neck end, and controlled and rocked upon itsv pivot in one direction by an endwise-moving sleeve engaging the upper surface of its projecting end, and in the other direction by a wedge carried by the sleeve riding under the lower surface of said end.

The object of the next part of my invention is to compensate wear of the chuck, or of its bearings, and enable it to run smoothly in the casing of the hand-piece, without wabbling or chattering,7 which wabbling and chattering movements, if imparted to the operating-tool, cause much annoyance to the operator, owing to the delicate work to be performed, and are plication for Letters Patent tiled by me Dealso disagreeable and annoying in a high degree to the patient who is undergoing the operation; to which ends my improvement consists in the combination, in a dental-engine hand-piece, of a casing, a rotary chuck mounted therein, with a screw-threaded end projecting beyond the end or nose of the casing, an internal pullbearing to prevent endwise movement of the chuck in the casing when a pulling-strain is exerted thereon, and an external adjustable push-bearing mounted upon the projecting screw-threaded end of the chuck bearing against and overlapping the tapering end of the nose, whereby the said tapering push-bearing may be adjusted to compensate wear of the chuck.

My invention further consists in a dentalengine hand-piece consisting of a casing, a chuck or mandrel mounted therein, separable from the driving-power, tool-locking mechanism carried by the chuck, and adjusting mechanism for compensating wear of the chuck or of its bearings in the casing.

In the accompanying drawings, which show my improvements as embodied in a dentalengine hand-piece in the best form now known to me, Figure 1 represents a View in elevation of the instrument, partly in section to show its internal parts; Fig.2,alongitudinal central section therethrough at right angles to the line of section taken in Fig. 1, showing the parts in their normal position; Fig. 3, a section similar to Fig. 2, showing the parts as retracted with the chuck, unclutched from the drivingpower, and the tool-lock raised to disengage its end from the grooved tool-shank; Fig. 4, a transverse section through the device on the line 4 4t of Figs. l and 2; and Fig. 5, a view in perspective of the beveled driving end or a tool-shank, with a locking-groove across the face of the beveled portion, to which form of tool-shank the locking-latch is adapted. Fig. 6 shows a detached view of the push-bearing and end of the casing and screw-threaded chuck.

' The sectional casing A of the hand-piece is shown as provided with a swiveling end section, a, connected with the free end of a flexible non-rotating sheath, B, so as to permit the casing freely to swivel to accommodate the turning movements of thehand ofthe operator; and in this casing is mounted a chuck, mandrel or tool-holder, provided at its front end with the usual socket, and adapted at its rear end for connection with the free end of a ilexible power-driven shaft, C, enveloped by the non-rotating sheath carrying the casing, as usual. This shaft and sheath is preferably that of the well-known S S. White Dental Engine.77 The rotary chuck is in this instance divided transversely near its rear end, and the adjacent ends of the sections D D thus formed are normally connected by a clutch or coupling, as shown in Gilbert7 s and my own patents, hereinbefore mentioned, and in apending apcember 14, 1877. The rear end of the front section, D, is centrally bored and its walls provided with notches or recesses chin which notches a cross-pin, e, carried by an endwisemovable rod, E, mounted in a central bore of the rear section, D', of the chuck, ordinarily interlocks, a spring, f, tending to keep the rod and its clutch-pin thrust forward. This clutch-rod is prevented from turning independently of section D and compelled to rotate with it, while allowed to move freely endwise, by a cross-pin, c', on the rod working in a longitudinal slot, d, in said section. This clutch mechanism is substantially similar to that shown in Gilberts patent of 1878, above mentioned, except that in this instance the endwise-moving clutch-rod does not carry or constitute the tool-locking devices, but projects only a short distance into the bore of the front section of the divided spindle or chuck. Upon this front section, D, is mounted an endwise-moving sleeve or thimble, F, acted upon by a spring, F', in a well-known way, which sleeve governs the movements of the tool-lock, as usual.

As before stated, in the present invention, the tool-locking devices and the clutch mechanism for controlling the rotation of the chuck are not directly connected, as in Gilberts patent; and in order to operate the two-mechanisms simultaneously and by a single movement, I employ an `intermediate independent mechanism, consisting in this instance of a rod or plunger, G, somewhat similar to the clutch-rod E, against which latter the rear inner end of the plunger G abuts, or nearly so. This plunger is movable endwise in the rear bore of section D of the chuck, and is connected with the controlling-sleeve F, with which 'it moves by means of a cross-pin, g,

working in a longitudinal slot, d2, of said section D. This pin and slot, while allowing the plunger to move freely endwise with the controlling-sleeve, prevents it from turning independently of the sleeve and the chucksection upon which it is mounted. It will thus be obvious that when the sleeve is retracted to disengage the tool-locking device from the tool-shank the plunger G will be caused to move backward, and its rear end be brought in contact with the front end of the rod carrying the clutch-pin, and thereby move said rod backward against the tension of its impelling-spring, thus disengaging the clutch-pin from the recessed end of sectionD of the chuck and stopping` the rotation of said section as long as the sleeve is retracted, as the two sections of the chuck will no longer be connected or coupled, while the rear sec- ICO IIO

tion, D', of the chuck will still be free to retwo devices-clutch and tool-lock-are thus operated by asingle movement without necessitating the release of the operators grasp upon the instrument. The instant the controllingsleeve is released its spring throws it forward, engaging thetool-lock with the tool-shank, if such there be inserted in the socket, and carrying the clutch-disengaging plunger out of contact with the clutch-rod, which rod is immediately thrown forward byits impellingspring to reclutch the chuck-sections. The chuck-sections, when properly coupled, owing to the formation of their bearings and the construction shown, work as perfectly as a solid chuck, which, in fact, it may be considered to be.

The controllingsleeve F is shown in the drawings as operated by an external sliding ring or linger-piece, H, of well-known construction, mounted upon the casing, the proper connection between the sleeve and ring being secured by an internal annulus,H, enveloping the sleeve and acting upon a shoulder thereof, the annulus being held from rotation by suitable screws, 7i, moving in longitudinal guide-slots in the casing when the nger-piece is manipulated. This controlling-sleeve might, however, be operated in other well -known ways; but I prefer the construction shown as more convenient.

A tool-locking latch, I, is pivoted at c' in a longitudinal slot in the chuck, and 'is provided in front of itsV pivot with a hooked end or downward projection, i, and an inclined surface for engagement, respectively, with the grooved shank and beveled or inclined driving end of an operating-tool, and in rear of its pivot is provided with an upwardly-projecting or goose-neck end, which lits in a longitudinal slot, f, in the spring-controlling sleeve, as clearly indicated in the drawings.

In rear of the pivoted latch inthe longitudinal slot in the chuck (which slot, however, is not so deep at this point as at the point where the latch is pivot-ed) is mounted a sliding wedge, J, connected with the controlling-sleeve, and provided with an inclined end adapted to ride under the goose-neck of the latch when thrust forward. This wedge also has an oblique shoulder or projection extending into the longitudinal slot of the thimble, in whichslot the gooseneck end of the catch lies when the wedgeis thrust forward.

The operation ofthe tool-lock is as follows: Supposing the parts to be in their normal position, as shown in Fig. 2, and a tool is to be inserted or removed, it is necessary to retract the controlling-sleeve to withdraw the wedge from beneath the neck of the latch, which latch is then rocked upon its pivot to raise its front end by the abutting or contact of the end wall of the slot in the sleeve against the upper surface of the projection or gooseneck end, thereby throwing the latch into the position shown in Fig. 3. This allows a toolshank to be inserted iu or removed from the socket. By releasing the sleeve, its spring throws it and the wedge forward, the incline of the latter riding under the goose-neck and forcing it upward into its seat in the longitudinal slot in the sleeve, and thereby bringing its front end down into engagement with the tool-shank, as clearly shown in Fig. 2, in which position of the latch the tool is firmly locked iu the socket of the chuck, and prevented from endwise or turning movements independently thereof, and can only be released by retracting the sleeve. Thus it will be seen that the latch is worked positively in both directions. The tool-lock, inthe present instance, is adapted to the form of tool-shank shown in Fig. 5, which has a beveled or flattened driving end, with a locking-groove running across the face of the beveled portion, between it and the round portion ofthe shank. The end of the chuck which is socketed for the reception of the operating-tools projects beyond the nose of the casing proper, and is provided with screw-threads, upon which is secured a push-bearing, K, having a flaring mouth to overlap and abut against the tapering end or nose ofthe casing. This push-bearing is thus rendered adjustable on the chuck to compensate any wear thereof or of its bearings, whereby I am enabled, in an easy and convenient manner, to prevent wabbling and chattering or" the chuck and tool mounted therein. The chuck, of course, has a suitable internal pull-bearing, and is locked from endwise movement in either direction.

The nose or end section,c,of the hand-piece casing is by preference constructed of hardened steel, as described and claimed in Letters Patent granted to me November 16, 1875, as No. 170,125, and the external push-bearing is likewise by preference constructed of hardened steel, the more effectually to resist wear between them when adjusted. I amenabled, also, by the construction shown, to furnish a long bearing in the chuck for the tool-shank, which is desirable.

The mode of operation and advantages of a dental-engine hand-piece constructed as hereinbefore described will be obvious without further description.

I claim as of my own invention 1. The combination, substantially as hereinbefore set forth, of the casing, the sectional spindle or chuck, the clutch between the chucksections,thepivoted rocking tool-locking latch, and a controlling-sleeve acting both upon the clutch and pivoted latch to simultaneously disengage the chuck-sections and rock the latch upon its pivot to free it from the tool-shank.

2. A pivoted tool-locking latch or catch for dental-engine hand-pieces, provided in front of its pivot with a projecting or hooked end and an incline or fiattened surface,and in rear of its pivot with an upwardly-projecting or goose-neck end, by which the latch is controlled or rocked upon its pivotto engage its front end with or disengage it from the tool-shank.

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lrevolving with the chuck enveloping and controlling the pivoted latch.

4. A pivoted tool-locking nach for dental! engine hand-pieces, having a projecting or goose-neck end, in combination with an endwise-moving sleeve carrying a wedge,whereby thc latch is positively rocked or operated in one direction by contact of the sleeve with the upper surface of the latch and in the other direction by the wedge riding under the neck or lower surface of the latch.

5. The combination, 'in a/dental-engine handpiece, of a casing, a rotary chuck mounted therein,with a screw-threaded end projecting beyond the end or nose of the casing, an in ternal pull-bearing to prevent endwise movement of the chuck in the casing, and an eX- ternal adjustable push-bearing mounted upon the projecting screw-threaded end ofthe chuck,

bearing against and overlapping the tapering end of the nose, whereby the said tapering` push-bearing may be adjusted to compensate wear of the chuck.

6. The combination of they casing, the sectional or divided chuck mounted in bearings in said casing, the clutch between said chucksections,c0nsisting of a rod movable endwise in one of said chuck-sections, and carrying a clutch pin or lug engaging a notch in the end of the opposite chuck-section, and an independent rod or connection and operating mechanism therefor to operate said clutch-rod,sub stantially as described.

7. The combination, substantially as here- .to inbefore set forth, of the slotted chuck, the pivoted goose-neck latch, the sliding wedge, and the slotted endwise-moving spring-controlling sleeve for governing the movements of the latch, whereby the latch is positively 45 operated in both directions.

In testimony whereof I have hereunto subscribed my name.

'ELI T. STARR.

Vitnesses:

J. A. B. WILLIAMS,

F. L. HIsE. 

